Circuit control system



y P. TALMEY 2,007,500

CIRCUIT CONTROL SYSTEM Original Filed July 17, 1931 Bu/ 7-. Qzzw BY ATTORNE;

Patented July 9, 1935 UNITED STATES- j 2,007,508 CIRCUIT CONTROL SYSTEM Paul Talmey, New Haven, Conn.

7 Application July 17, 1931, Serial No. 551,434 Renewed November 6, 1934.

v Claims. (Cl. 123-145) My invention can be used as a control for electric incandescent igniters wherein it is desired to control the current through the ignition element by the rate of flow of gases in the intake 5 or the exhaust, or the rate of flow of gases in the cylinder or cylinders, in which case it shall be so designed that before starting, or at low speeds as in starting, this control will have a'high electrical resistance. While working onigniters of the electric incandescent type I found that it was desirable to increase the resistance external to the igniting element itself prior to starting and to decrease this resistance after starting. In order to achieve this effect automatically I place in the intake air stream a flowmeter of the thermal type which consists of a hot element placed in the fluid stream, the resistance of the hot element being a function of the flow of fluid over the element, the resistance being greatest at zero flow and least at the highest rate of flow. Prior to starting the rate of flow in the intake manifold (for example) is zero. After starting the rate of flow increases with speed. It is obvious then that if the flowmeter element'is placed in. series with the igniter the resistance is greatest prior to starting and less after starting, decreasing with speed, in other words. After starting, the cool intake gases flowing over the substance of this control will decrease this resistance and provide for sufficient current increase for running, increasing the current further with increased speed.

The foregoing and other features of my invention will now be described in connection with the accompanying drawing forming part of this specification in which I have represented my circuit control system in its preferred form, after which I shall point out more particularly in the claims those features which I believe'to be new and of my own invention.

The figure is a diagrammatic sketch showing my element as a starting control for electric incandescent igniters for an internal combustion engine.

The material of the elements is also a matter dependent on the conditions, having preferably a high temperature coeflicient of resistivity a high melting point and a low rate of volatilization and oxidation. For general work platinum is perhaps the most suitable, although iron would be the most sensitive. In reducing atmospheres or mediums at high temperatures, or wherever strength is necessary at low temperatures, tungsten elements are very suitable. Where negative temperature coefficients of resistivity are desired carbon or certain refractory substances, such as thorium oxide or certain alloys such as Ia Ia can be used.

Combinations can be used of various elements in series and/or shunt with various total resistances, and/or temperature coeflicien'ts of resistivity and/or dimensions to obtain the desired temperature, rate of flow, resistance relations.

The phrase rate of flow of the fluid is to be considered as any motion of the fluid relative to the element which can increase the rate of dissipation of heat. Zero rate of flow can be taken at any arbitrary pressure or temperature ina still fluid.

The figure shows a flowmeter of parts A, B, D and H wherein A and B are electrodes mounted in a detachable plug H and supporting a hot element D which is in the fluid stream. D is heated by the current flowing through it. F is any portion of the engine or any suitable support placed in'or around the engine. M represents a set of igniters of the electric incandescent type the hot or incandescent elements of which are placed in the combustion chambers of the several cylinders. As these igniters are not a portion of the invention described herein, I do not wish to limit myself to this arrangement alone of the igniters or any other auxiliary parts to the system other than the particular flowmeter herein described. It is also customary to have a battery and an additional variable resistance for manual control as shown.

Current from the battery flows through the igniters heating them as well as the element D. After starting the gas flowing over D decreases its temperature and hence its resistance by the well known temperature resistance effect. Hence after starting the flowmeter has less resistance than prior to starting. Assuming (for simplicity only) that the resistance of the igniters remains constant then the current through them increases after starting. Thus this objective is accomplished.

I wish to point out that the combination of. a flowmeter and an electric igniter system can be arranged in a variety of useful ways other than the one pointed out in particular above. With different types of systems the problems are different, but the essential principle of a flowmeter of the type described immersed in a fluid stream to further control the current through the igniters which constitutes my invention remains the same no matter where the fluid stream is located or in what manner the flowmeter is connected to the igniters.

Since igniters having a hot element are in general incandescent, I have used this term but I wish to point out that it is possible to have an igniter which is not truly incandescent but is sufliciently hot to ignite the fuel without glowing. I wish to include all such types in the term incandescent igniters.

With any hook up I found less current was required during starting than while running, due to the fact that there is less heat dissipation as there are no cold gases being drawn into the cylinder. In order to get around this difficulty there must be inserted in the circuit an additional resistance of approximately less than one-half of an ohm while starting. In order to get this resistance into the circuit during starting only and then to cut it out when the engine picks up, I plan to use a resistance wire inserted in the air intake, such that with no cold gas blowing over it, it will heat up to a temperature of about 600 degrees 0., which I believe will not ignite any gasoline vapor present. When cold gas is blown over this hot wire it should cool it down to about 200 degrees C. Considering a temperature difierence between the stationary condition and the running condition of about 400 degrees we can use a pure iron wire, the resistance of which will be 4.8 times greater at the stationary condition than at the running condition. Therefore, if. we use about 6 of an ohm while running we will have .48 at starting. The wire must be sufiiciently fine to follow the temperatures. In order to do this we can use a multiplicity of fine wires. They can be mounted in a plug similar to the regular ignition plug which can be screwed into a threaded hole in the air intake side of the carburetor. The plug will have two electrodes instead of three, both insulated from the plug, with about one-half an inch between them. It may be necessary to put some sort of a coating of nickel over the wire to prevent oxidation.

I wish it distinctly understood that my control system herein described and illustrated is in the form in which I desire to construct it and that changes or variations may be made as may be convenient or desirable without departing from the salient features of my invention and I therefore intend the following claims to cover such modifications as naturally fall within the lines of invention.

I claim:-

1. In a device of the class described in combination, a flowmeter with an electric incandescent igniter system whereby the current through the igniters is controlled.

2. In a device of. the class described in combina tion, a flowmeter, with an electric incandescent igniter system, means whereby the current through the igniters is controlled.

3. The device of claim 1, the heated element of the fiowmeter is connected in series with the igniters.

4. In a device of the class described in combination, a flowmeter having its heated element connected with an electric incandescent igniter system whereby the current through the igniters is controlled by the change of resistance in the heated element.

5. An ignition system for internal combustion engines comprising igniting the inflammable mixture by an electric incandescent igniter, controlling the current thru the igniter' by electrical resistance internal to the combustion chamber.

PAUL TALMEY. 

